Method and system for processing a discrete time input signal where the clock rate of a discrete time output signal is a multiple of the clock rate of input signal samples
AssigneeASML Holding N.V.
InventorRoberto B. Wiener
Life of this patent
Estimating the term…
Abstract
A method and system of efficiently processing a discrete time input signal having a plurality of input signal samples that occur at a first clock rate into a discrete time output signal having a second clock rate that is R times the first clock rate is presented. The method includes receiving the input signal and filtering the input signal with an N-taps finite impulse response (FIR) filter having N filter coefficients. The method reduces the number of required operations and reduces computational errors in the filtering and interpolation of discrete input signals.
Claims8
A method of efficiently processing a discrete time input signal having a plurality of input signal samples that occur at a first clock rate into a discrete time output signal having a second clock rate that is R times the first clock rate, the method comprising the steps of:
- receiving the input signal;
- and
- filtering the input signal with an N-taps finite impulse response (FIR) filter having N filter coefficients according to
- ∑
- i
- =
- k
- ceil
-
- [
- (
- N
- +
- 1
- -
- k
- )
- /
- R
- ]
- -
- 1
-
- b
- iR
- -
- k
-
- u
-
- (
- (
- m
- -
- i
- +
- k
- )
-
- T
- s
- )
- wherein biR−k is one of the N filter coefficients, u((m−i+k)Ts) is one of the input signal samples, Ts is a slow clock sampling period, m equals (0, 1, 2, 3, . . . ), and k equals (0, 1, 2, . . . , R−1).
A system for efficiently processing a discrete time input signal having a plurality of input signal samples that occur at a first clock rate into a discrete time output signal having a second clock rate that is R times the first clock rate, the system comprising:
- means for receiving the input signal;
- and
- means for filtering the input signal with an N-taps finite impulse response (FIR) filter having N filter coefficients according to
- ∑
- i
- =
- k
- ceil
-
- [
- (
- N
- +
- 1
- -
- k
- )
- /
- R
- ]
- -
- 1
-
- b
- iR
- -
- k
-
- u
-
- (
- (
- m
- -
- i
- +
- k
- )
-
- T
- s
- )
- wherein biR−k is one of the N filter coefficients, u((m−i+k)Ts) is one of the input signal samples, Ts is a slow clock sampling period, m equals (0, 1, 2, 3, . . . ), and k equals (0, 1, 2, . . . , R−1).
Dependencies are inferred from the claim text.